Often people spend a lot of time reading aloud, but not much time listening. Try recording your voice as you are reading or speaking aloud. Use a tape recorder, CD burner, or PC.
When listening to the playback of your voice, analyse your sentence. eg How was your grammar? Did you speak with the right inflection, etc.
Then try something even tougher. Write a list of possible interview questions (10 or so), do not write down the answers. Then read aloud the question, and speak the answer to them spontaneously into your tape recorder. Analyse each of your answers. Try writing down the answers you have recorded and see if they make grammatical sense. See if you make filler sounds like "um" or "er".
Finally, ask friends to listen to your taped answers and get them to make suggestions. (Make sure it isn't too long).
